An Investigation of Effect of Low-Gradient Stepped Cascade with Different End Sill Shapes on Aeration Performance of Marginal Water

Abstract

The primary purpose of water aeration is to increase the oxygen saturation of the water. This can be achieved by using hydraulic structures because of substantial air bubble entrainment at these structures. In a stepped cascade, the provision of steps can produce significant energy dissipation. Efforts to increase the DO level of rivers require significant expenditures each year . Organic waste from municipal, agricultural, and industrial sources may overload the natural system causing a serious depletion of the oxygen supply in the water . In this study the aeration efficiency of Low-Gradient stepped cascade for polluted water is studied and the effect of COD on aeration efficiency is presented.

Keywords: stepped cascade weir, aeration , COD ,Dissolved Oxygen, Marginal water